The invention relates to glass articles having a roughened surface. More particularly, the invention relates to glass articles having a roughened peripheral surface or edge that is capable of scattering incident light. Even more particularly, the invention relates to a glass article having an edge that has been roughened by etching the edge.
Glass articles, such as liquid crystal display image masks, require relatively smooth, polished planar surfaces that are free of physical defects or contamination. A rogue contaminant particle, if pulled across the polished planar surface may, for example, mechanically abrade the surface, producing a physical dig or subsurface damage. Particle contamination may be generated by the release of trapped debris (e.g., glass chips, lapping and/or polishing compounds) originating from the ground edge of the glass article during handling or from ultrasonic cleaning. The released debris may work itself onto the polished surface of the article. Another source of contamination is crack propagation originating from subsurface damage. Such crack propagation releases glass chips from the ground edge.
Glass articles such as image masks are often provided with ground or otherwise roughened edges. Because of their light scattering properties, such roughened edges assist in alignment of the glass article. In addition, roughened edges facilitate manual handling of the glass article. However, ground edges also act as a major source of debris that may damage the polished surfaces of the article. Thus, while providing a glass article with roughened edges is highly desirable, it also is a major source of contamination. While polishing the edge drastically reduces the amount of debris, the resulting surface does not satisfactorily scatter light or facilitate handling of the article.
Therefore, what is needed is a glass article having an edge that is capable of scattering light and/or facilitating handling, wherein the edge has a low level of release of debris. What is also needed is a method of making such an edge.